The Manhattan Project

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Philip Abelson's Interview (1966)

Dr. Philip Abelson was a physicist on the path to discovering fission when Otto Hahn and Lisa Meitner discovered this process first. Abelson worked at the Navy Research Laboratory in Philadelphia, where he designed pipes to enrich uranium. He discusses how he was also the first in the United States to manufacture large quantities of uranium hexafluoride. Abelson’s technology was reviewed by General Leslie R. Groves, Edward Teller, and J. Robert Oppenheimer. His research led to the rapid construction of the S-50 Plant in Oak Ridge, the liquid thermal diffusion plant. He recalls the challenges of designing pipes for uranium enrichment.

Philip Abelson: I went to the Lawrence Berkeley Laboratory in the fall of 1935 as a graduate student in the Radiation Laboratory. I had had some background in chemistry. I hadn’t been there more than about six months before [Ernest] Lawrence, one day, suggested to me that I should look into the phenomena accompanying neutron irradiation of uranium.

Fermi had reported making transuranic elements from neutrons plus uranium. And Lawrence was doubtful of the validity of these experiments, and he was correct in being doubtful as it turned out.

Groueff: The Fermi experiments were in ’34?

Abelson: Fermi started, but he reported them in a series of papers that went on to ’34, ’35, and so on. What he had found out irradiating other things is that when you irradiated an element, you got radioactivity, and this emits an electron which makes the nucleus go to a higher atomic number. He thought that he had elements beyond uranium.

So Lawrence suggested that I should study this, and the other thing was that I should look for alpha particles. These should have accompanied this product in this irradiation. We didn’t have very good equipment. I looked and I didn’t find the alpha particles, but I continued to study the irradiation of uranium. So I was perhaps the one person in this country that was studying uranium fission before 1939.

Groueff: You were a physicist?

Abelson: I was a physicist, a graduate student at the time.

Groueff: Where did you study, in Berkeley?

Abelson: Yes, I was a graduate student in Berkeley. I was working for my PhD degree in Berkeley. I had done undergraduate work elsewhere. This went on, and I could tell you more of the detail of my several years work, but I won’t go into it too much.

At any rate, I was making some experiments with X-ray detection of the radiation emitted by the radioactivity that probably would have lead me to discover a uranium fission, because I had a method of looking at it. I was on the right track. I did not in time, so then there was this announcement of [Otto] Hahn and [Lisa] Meitner and the discovery of fission. And within two days after that announcement, I had confirmed it and had identified this X-ray to be an X-ray from iodine. I had proved that iodine was a fission product of uranium.

I was the first person in this country to identify the number of the fission products, and this was the basis of my PhD thesis. I got my PhD degree, and I came back here to Washington in September of 1939 to help build a cyclotron at the Carnegie Institution in Washington in the Department of Terrestrial Magnetism here in the city. I didn’t do much with uranium, but in January and February of 1940, I concluded that the uranium was decaying into neptunium and neptunium was decaying into plutonium, and I devised means for how to prove it.

I did a few experiments here, but we didn’t have very good intensity radiation, so I went out to Berkeley. When I got out there, I found that Professor [Edwin] McMillan also had the same news so we joined together. And within a week we found and confirmed it.

Groueff: You were one of what, three or four?

Abelson: No, just two of us.

Groueff: McMillan and you?

Abelson: So this was all done within a week in May of 1940. Then I returned to Washington. I was just there for a brief time. When I came back to Washington, by this time France had fallen. Already the scientists in this country were beginning to mobilize. Already also by this time, Lyman Briggs had been appointed chairman of the Uranium Committee. Merle Tuve too was a member. Harold Urey was a member, Jesse Beams.

Groueff: [Eger] Murphree?

Abelson: No, Murphree a little later. Gregory Breit was on it and Ross Gunn was on it. Lyman Briggs needed to have, you might say, a technical advisor that he could consult at any time, so I was the technical advisor. It was an informal relationship, but I was there and I wrote many of the letters for him at that time during the autumn of 1940 and early 1941. This didn’t take all of my time.

I started looking around to see what method might be employed to separate uranium isotopes. It looked like a terrible, terrible job. It was a job like nothing that had been done before and only in very small amounts of any of these elements. Some Lithium-6 and 7 had been separated. Here was a mass difference of one part in six. And we were going to try to separate uranium with three parts in two hundred.

Then also, it was soon very evident that there was a difficult problem with respect to the chemicals one might choose. The chemistry of uranium wasn’t well-known, and the chemicals weren’t very satisfactory things to deal with. But I looked around for various separation schemes, and my eyes fell on liquid thermal diffusion. This seemed to me something that might be pretty simple and something which also might have potentiality for handling fairly substantial amounts, so I just built some simple columns.

Groueff: That process existed for other users?

Abelson: What had happened was that there had been some studies in which water solutions of salts had been separated. Some small isotope effects had been observed, but these were water solutions. I ran a few solutions of the uranium, and I could see that water solutions of the uranium were never going to work. So I looked around to see what kind of a chemical substance of uranium might there be that was stable, and which would be a liquid itself. I saw that uranium hexafluoride might be suitable. At that time, only a few grams of uranium hexafluoride had ever been made.

Groueff: Isn’t that a gas?

Abelson: It is a substance which below fifty-six degrees centigrade is a solid. And at two atmospheric pressures it melts at about sixty-eight degrees centigrade. If you have enough pressure on it, you can get it to a higher temperature and keep it a liquid. So I could see that if I were going to conduct any experiments of uranium hexafluoride, I had to get the uranium hexafluoride.

This could not be bought. Nobody made it, so I must make some. I looked around to see how this should be made, and I devised a scheme for making uranium hexafluoride in good quantities by making first UF4 and then converting this to UF6. So I personally made the first several hundred pounds of uranium hexafluoride that was made in this country.

Groueff: You’re not a chemist?

Abelson: I had a Bachelor’s degree in chemistry. In the early days, I shipped uranium hexafluoride to Columbia University and to other people – [John] Dunning and Beams – that were interested. I sent out several hundred pounds of uranium hexafluoride.

Groueff: You were making it here in Washington?

Abelson: In Washington. I made it first at the Bureau of Standards, and then in June of 1941 I went to the Naval Research Laboratory with Ross Gunn. In early 1941 I saw that there was going to be an expanded effort probably in the uranium field, and I also saw that energetic people such as Ernest Lawrence and Compton were going to push Briggs aside.

Briggs, of course, did not know nuclear physics. He’s a fine old gentlemen and a very good man, but he was too old to lead a vigorous activity. This required young, imaginative, and driving people. And Briggs was not of the generation or background to lead this thing. I saw that if I wanted to make a contribution, I must make it by separating uranium isotopes.

In order to get bigger equipment, it was going to require longer columns and so on. I made arrangements with Ross Gunn down at the Naval Research Laboratory. There I started making very big columns. I did some work – I don’t know how much it interacted with the Columbia group – but I did some work with pure nickel. I did some work which I applied at any rate with my equipment in pre-treating it with fluorine to coat with fluoride and remove anything that would react with uranium hexafluoride.

I conducted a lot of stability tests. I found out how to handle the uranium hexafluoride and how to have it in the equipment without having it decompose or react with the wrong substances. I had by this time one assistant, John Hoover. Together, we made a number of experiments with different geometry of these columns. We got some encouraging results by July 1942.

Groueff: At the Naval Research?

Abelson: At the Naval Research.

Groueff: What was your position there? It was a military thing, right?

Abelson: Yes, but the staff at the Naval Research Laboratory was largely civilian. And while it was naval research and the director was a naval officer and there were some naval officers there, the naval officers did not interfere with our conduct of experimentation. I didn’t conduct my scientific investigations any differently than I would in a civilian laboratory.

Groueff: So they gave you a facility, a corner in a laboratory?

Abelson: They gave me a facility.

Groueff: And that was your responsibility?

Abelson: That was my responsibility. Nor did Dr. Gunn interfere in any way. These people supported me.

Groueff: They gave you all of the materials?

Abelson: They gave me the materials and the equipment.

Groueff: Why did they do that?

Abelson: The reason why was that Dr. Gunn had been interested in the uranium in the first place. The Navy had long been looking for a better way of propulsion of submarines. They tried fuel cells already. In fact, immediately after the announcement of uranium fission, Gunn became active in this field, and this was for the purpose of getting nuclear propulsion. This was in 1939, early 1940. The reason why I was brought down there was for the purpose of nuclear propulsion.

Groueff: Not the bomb?

Abelson: Not a bomb. Of course everything was secret, but one found out some things. We early on learned that there was a close question whether one was going to be able to have a chain reactor with natural material. But it was also very evident that if you could enrich the material a little bit, instead of being a reactor as big as a house, it was down as big as a room. So it was clear that being able to separate uranium and to enrich it from seven-tenths to nine-tenths percent U-235 would change the whole complexion of nuclear propulsion for the Navy.

Groueff: So that explains your interest in separating U-235 was not for bomb purposes, but in order to have enriched materials?

Abelson: Yeah, this was our reason in pushing it in the Navy. And then of course, naturally, I learned of the activity of the Manhattan District. I could see that we could carry on some partial separation of uranium and get it part of the way. We could do this quite cheaply and we could do it very fast.

But I could also see that to carry the uranium all the way to ninety percent U-235 was going to take probably too long. It was going to take several years because the equilibrium time was long. But this did not mean that it’s still going to be useful. The point was that this equipment was ridiculously simple. All it consisted of was three concentric pipes. This is all you had to put together and put heat in the middle and cool on the outside and uranium isotopes separate in between.

Groueff: So the light goes to the top?

Abelson: The light goes to the top and climbs, and then heavy goes down, so that all one has to do is to fill this thing and put steam in and cooling water and go away for three days and one has separation. It was so ridiculously simple.

Groueff: And it worked?

Abelson: Yeah, it worked.

Groueff: The uranium circulated in between?

Abelson: This is what happens. We had some columns in which we took from the top uranium that was already carried up from .7 up to 1.4. This could be done in just one forty-eight foot column. But this one had to wait. It was very easy to run where one went from .7 to .84, and then one could milk off the product on top.

Then incidentally, I was again the first person in this country to separate, to make substantial separations of a real quantity of uranium. By early 1943, I shipped to Chicago some twenty or thirty pounds of uranium hexafluoride, and it made quite a difference in the isotope content.

Groueff: That you produced here?

Abelson: I produced it here in small pilot plants.

Groueff: Did you design the installation, the equipment, the tubes, the pipes, the columns, with the specifications of whether they’re forty-eight feet long, or nickel and copper?

Abelson: Yeah.

Groueff: Are the thin pipes?

Abelson: Forty-eight feet long, but in nickel of about an eighth of an inch thick and about one and five-eighths inch in diameter.

Groueff: They were two inches in diameter?

Abelson: Yeah, and then there was this other

Groueff: So they were very thin?

Abelson: I’m very poor at drawing, but then the uranium was in the space like this.

Groueff: And not bigger than that?

Abelson: Actually, it was only a ten-thousandth of an inch thick where the uranium was. It’s very thin. Now, this was the cold copper and then there was a big iron pipe around it with water.

Groueff: But the whole diameter of the whole column was a few inches?

Abelson: The total including the outer water jacket was four inches.

Groueff: I imagined that the place between the two tubes where the uranium hexafluoride ran was substantially large, but you say it’s so thin. And in this thin space, how could the isotope choose between the hot and the cool?

Abelson: We had a temperature in here of two hundred and eighty degrees centigrade, and a temperature here of seventy degrees centigrade. Across this very, very thin layer was a difference in temperature of two hundred degrees.

Groueff: I see. In other words, the outer tube was not cold. It was seventy degrees.

Abelson: You had to keep it above the melting temperature.

Groueff: You wouldn’t call it cold. Seventy degrees is quite warm.

Abelson: Yeah, you’d be uncomfortable at seventy degrees.

Groueff: Yeah, it would be hot. And it was made of nickel because of the corrosion?

Abelson: It had to be nickel here. This is nickel, and this was—

Groueff: Copper?

Abelson: Copper.

Groueff: Does the copper resist—

Abelson: The copper is not as good as the nickel, but since it was only at seventy degrees centigrade it was all right.

Groueff: It wasn’t corroded by the hexafluoride?

Abelson: No, not at seventy degrees. It’s not enough to be troublesome. Of course, the nickel didn’t corrode at all, even at two hundred and eighty degrees.

Groueff: And I understand you needed a tremendous amount of steam?

Abelson: Yeah, a very, very great amount of heat.

Groueff: In other words, the Naval Research gave you all the facilities and the credits and the instruments and the materials, and let you be independent there. But was Dr. Gunn in the capacity of a scientist working with you or administratively?

Abelson: Ross Gunn was the top technical man in the Naval Research Laboratory. He was also superintendent of the division in which I worked, so that I reported to him. He was my boss, you might say.

Groueff: But not a collaborator?

Abelson: No.

Groueff: He’s not an experimental scientist?

Abelson: He’s a physicist, but he never participated in any of the experiments.

Groueff: But he was the boss to decide to whether, let’s say, to cooperate with the Manhattan Project or not?

Abelson: Yeah. One must remember that there had been Army/Navy rivalry. It was pretty intense before the war. The other thing that had happened was that Gunn, of course, had been interested in this. He was seeking nuclear propulsion, and he had been on this committee. So then there was a series of reorganizations of the committee. By the time General Groves came to the laboratory, Ross Gunn had already been sort of dumped so that he was bruised and bleeding.

Groueff: Was he an old man or a young man?

Abelson: He’s now about seventy, but at that time he was forty-five.

Groueff: So you prepared this, but you were not in touch with the S-1 committee until the visit of Groves?

Abelson: When Groves came down, the people got some information about what we had done. When they looked at it in terms of being the sole method of enriching uranium all the way, I could myself see that this wasn’t the way to go all the way. So they decided that they weren’t—

Groueff: Interested?

Abelson: Interested. And in fact, at that time, actually sought to stop our work, but they didn’t succeed. So we went ahead anyway. I had enough communication with the people at Columbia to know that they were having trouble. We didn’t have too much communication because of secrecy. But without going into detail of what the problem was, I learned that there were difficulties.

I can visualize that for a relatively modest amount of money, we could separate enough uranium to be really interesting with respect to reactors. So I pursued this one. Then I pursued it to the extent that we got authorization to build a pilot plant up in the Philadelphia Navy Yard. This was ultimately to be three hundred of these forty-eight feet columns.

They had some big boilers up there. It was a Naval Boiler and Turbine Laboratory. They had big boilers that were destined for battleships. They would run these boilers and then train green crews on the boilers on land. There was a boiler capacity available and there were people to run the boilers.

Groueff: To make the steam for you?

Abelson: To make the steam. Then we had a building that we could put our columns in. Arrangements were made for us to expand the plant up there. All this began about October or November 1943. By May or June we were already making good progress. This is all very secret and we were in a Navy Shipyard and there was much submarine damage, and priorities had to go to repairing ships. So our priority in the Navy Yard was priority twenty-three. There were only twenty-three priorities at that time.

I had four other associates: John Hoover, and three others. We just literally talked our way into getting people to work for us. The Navy Yard was big with tens of thousands of people working at that time. The organization of this thing was sufficiently loose that we could talk people into coming over and work for us. In this way with salesmanship and one thing or another, we began putting the plant together.

One thing we deliberately did was to design something that could be replicated. Our design, as it turned out, could have been better. We didn’t have mechanical engineers. We were our own mechanical engineers. Nevertheless, we had a rack with a hundred columns, and we fixed it up so that if somebody needed at Oak Ridge to build more of these things, all they had to do was to take this unit and copy it. That was our plan in doing it.

As it turned out, if we had had a little bit better engineering associated with us, we would have been better off. But it was simple things – using welding techniques instead of fittings and so on. We proceeded and we got this hundred-unit plant pretty well on the way to completion.

Then having done this, I heard another report from Columbia that things were going great down there. So at this time there was person who was going out to Los Alamos. I saw to it that he got a copy of our report of what we were doing.

Groueff: You knew about Los Alamos?

Abelson: I didn’t even know the name of Los Alamos, but I knew that there was a center out there. So I saw to it that a copy of our report got out there, and it first of all incidentally got to the attention of Edward Teller. And Edward Teller, after reading this report, talked to—

Groueff: Oppenheimer.

Abelson: Talked to Oppenheimer, and then Oppenheimer to Groves.

Groueff: So it wasn’t a visit of Oppenheimer here?

Abelson: No.

Groueff: It was true the other way.

Abelson: It was the other way. And it was on the basis of a report I had written that Teller read that—this led the action.

Groueff: In other words, this compartmentalization worked, but among scientists you knew there was a group in Chicago and another one in Los Alamos?

Abelson: Yeah, I knew that they were there, but only because I had a fairly good intelligence system of my own. This was only about how things in general were going and not matters of detail in progress, but it was having a general picture of how it was going.

Groueff: Your colleagues and friends were working there? McMillan was working in Los Alamos?

Abelson: Yeah. I forget how I learned about that. But I had learned, for instance, that the electromagnetic thing was coming along and that the other wasn’t. I had even thought of the value of our material, and there was an incentive to let these people know.

Groueff: So the channel was you to Teller, to Oppenheimer, and to Groves. And Groves realized the new picture that would result. Then Groves appointed a committee I think, or came himself to see?

Abelson: Groves came and there were several other scientists with him. One of course was the distinguished physical chemist from Caltech who was a technical advisor. I forget his name at the moment.

Groueff: [Richard] Tolman?

Abelson: Tolman was along.

Groueff: And Lewis?

Abelson: I don’t know whether Lewis was along at that time or not. I just remember Tolman.

Groueff: And Groves?

Abelson: And Groves.

Groueff: What was your contact with Groves up until that time? Or did you have none?

Abelson: Essentially none.

Groueff: He was just an officer that you met?

Abelson: That’s right.

Groueff: And then they decided to build a copy?

Abelson: They decided to build a copy of it in Oak Ridge. They brought in the Ferguson Company to do that.

Groueff: The Ferguson Company was given your draft and designs?

Abelson: Yeah.

Groueff: With an order to do it in six months and then three months? They did it in record time?

Abelson: They did it very fast. General Groves assigned an engineering officer, Mark Fox, and Fox is a very good expediter.

Groueff: Like Groves was?

Abelson: Yeah.

Groueff: I saw he wrote a paper on the building in an engineering journal.

Abelson: Yes. Then there was some delay. The thing was built fast, but there were naturally some bugs in this, as always in a plant that’s built very fast. But the other thing was that perhaps the choice of Ferguson was not as inspired as it might have been. They were a fine construction firm, but they were not an operating firm. There’s a lot of difference between putting a plant together and operating it, and operating it successfully and well. There are techniques of operation and one must have shift bosses and a group of people.

Groueff: For the gaseous diffusion they chose two companies, Kellex to build it and then Carbide to operate it.

Abelson: Custom operations.

Groueff: Or Eastman for electromagnetics, and Stone & Webster.

Abelson: Yeah.

Groueff: So in your case, there was only Ferguson?

Abelson: Only Ferguson. And Ferguson then made a Fercleve subsidiary, but Fercleve was created from nothing. So this, in wartime when there were no people really available for operating, during the running of the S-50 plant, quite a fraction of the people that actually operated it were young men who were in the service.

Groueff: With no idea?

Abelson: Never had any experience in plant operations.

Groueff: Did you teach them?

Abelson: I sought to teach them some, but after all, I was not an experienced plant superintendent. But a man gives many years, his life, to working up into an organization, and he understands what you must do to organize the steady operation of a plant.

Groueff: All the human problems.

Abelson: All the human problems and the rest of it with the training aspects.

Groueff: But did you personally—

Abelson: I was in Oak Ridge.

Groueff: You lived there?

Abelson: I lived there. Sure.

Groueff: So you moved from here to Oak Ridge during the construction and you worked with the Ferguson people?

Abelson: I was in Washington part of the time. I was in Philadelphia part of the time. I was in Oak Ridge part of the time.

Groueff: So you became a part of the Manhattan Project, and were still with the Naval Research Yard?

Abelson: Yes.

Groueff: What would you say were the main difficulties in the building? Was it the restriction of the industry, because they had two thousand and something—

Abelson: Actually, these columns were so simple that there weren’t that many problems. I would say that the problems that were involved were, among other things, getting proper care in the spacing of these. That is, if you are trying to have a separate of ten-thousandths of an inch and it’s twelve-thousandths on this side and eight-thousandths on that side, it makes a difference. So the problem of quality control was very difficult.

We had good quality control when we were doing it at the Naval Research Laboratory and fair quality control at the Navy Shipyard. But when these things were manufactured by the hundreds, there was as good a quality control as we had when we were doing it ourselves. So there was a quality control thing, which is just one of those things that has to happen in wartime, even when you’re in a hurry.

Groueff: And out of more than two thousand columns, and when you play with thousandths of an inch – the precision had to be almost perfect?

Abelson: The precision had to be very good.

Groueff: With the roundness of the pipe?

Abelson: With the roundness of the pipe. You get pipes that were oval and so on. As I say, when we were doing it ourselves, then we took the care to select materials and then discarding those that weren’t quite right.

Groueff: You could do it one by one?

Abelson: You can do it one by one or by the dozens, and especially if you have people who understand the importance of having it right. On the other hand, if you put a job like this out to a manufacturer who is judged on how many units he produces and how fast he can put it together—

Groueff: Yeah, because they didn’t have an idea why.

Abelson: They couldn’t be told too much. And while it was emphasized that it was supposed to be like this, it really takes very responsible dedicated people to guarantee quality control. Again, I suspect if it was something involving a company that really understood quality control, than it would have come out better.

Groueff: But you say this space is one-thousandth of an inch?

Abelson: It was ten-thousandths of an inch. But what I’m saying now is that what if the ten-thousandth becomes eleven-thousandth, and then it got to be nine over here?

Groueff: It’s like a sheet of paper?

Abelson: I forget, but a millimeter is forty-thousandths of an inch. So this is a quarter of a millimeter.

Groueff: So to the eye of an outsider it would look like a piece of paper? The two pipes were practically touching each other?

Abelson: Yeah.

Groueff: By the way, did you finish it by doing it liquid or a gas?

Abelson: Liquid.

Groueff: So not a gas? So the main difficulty was the quality?

Abelson: Quality control.

Groueff: And of course the quantity?

Abelson: Quality, quantity.

Groueff: Who was the boss of the job there? Was it Fox?

Abelson: Fox was the Army Engineer in charge. As such, he was really the fellow that was the boss. He was the one that had the say. And of course, the Ferguson people were doing what he said to do.

Groueff: Is he a bossy type or energetic?

Abelson: Energetic. He was for driving people, but not bossy in the sense that he just pushed people around to push them. He was pushing people around in order to get his job done.

Groueff: Did you have contacts at that time with Groves or Nichols?

Abelson: I had some contacts with Nichols and I had a few contacts with Groves. I saw more of Nichols than I did of Groves, but I was in essentially daily contact with Fox.

Groueff: And your reports were good with them? Your relationship was good?

Abelson: Yeah.

Groueff: There were no big conflicts?

Abelson: No.

Groueff: Like Groves had with others?

Abelson: No, there weren’t any conflicts.

Groueff: Do you remember anything colorful about some of the Ferguson people? Or were they just the builders?

Abelson: Wells Thompson wasn’t down there. They were good men that they had. I would say that the most colorful fellow was Fox.

Groueff: So you started production by the end of ’44?

Abelson: Uh-huh.

Groueff: And just in time for producing that for electromagnetics?

Abelson: Yeah.

Groueff: And then the electromagnetics was fed by you by the gaseous diffusion at the end?

Abelson: Yeah.

Groueff: And by their own alpha? All this from the natural uranium with different sources became enriched, which was then enriched more by the electromagnetics? You never went beyond that?

Abelson: No.

Groueff: Was it dismantled after the war?

Abelson: Yeah, after the war. Up in Philadelphia, we carried it on. We actually produced some material that was two and a half percent U-235 by cascading these things at the end of the war; then it was evident that the gaseous diffusion was going to work well. And of course, there wasn’t any point then in pursuing it further.

Groueff: Electromagnetics was also dismantled?

Abelson: Electromagnetics was also dismantled.

Groueff: But during those months of spring and the early summer of ’45 when the bomb was ready, you were there working?

Abelson: Yes, I was much of the time partly in Philadelphia and partly in Oak Ridge. I went back and forth.

Groueff: But you didn’t have a permanent sort of an official position with S-50? You were not the head?

Abelson: No, someone else was the so-called technical director. But what it amounted to was that they said, “Wherever he sits, it’s the head of the table.”

Groueff: But you were not involved once the uranium was produced by the thermal diffusion? The next steps were not your concern?

Abelson: No, that wasn’t my jurisdiction.

Groueff: Tell me a few words about your background. Are you Californian?

Abelson: I’m from the state of Washington.

Groueff: And you went to California?

Abelson: Yes, I had my Bachelor’s degree and Master’s degree at what’s now Washington State University in Pullman, Washington. Then I went to Berkeley for my PhD degree. And since 1939, I have been essentially in Washington.

Groueff: D.C.?

Abelson: D.C.

Groueff: And not in your state?

Abelson: No, in Washington, D.C.

One thing I did right after the war in September 1945 was to arrange for some of us to go to Hanford. It was then arranged for me to go to Oak Ridge to learn the reactor techniques. So by March or April 1946, I and a small group prepared a feasibility report on an atomic submarine. We said in that report that the major value of the submarine would be as a platform for nuclear-tipped rocket missiles.

Groueff: Even then?

Abelson: Yeah, 1946.

Groueff: Was [Admiral Hyman] Rickover a part of this group?

Abelson: No. He was completely separate and started about two years later.

Groueff: But during the war, this Naval Research Laboratory was not in any contact?

Abelson: Was not in any contact whatsoever.

Groueff: Ross Gunn was directly associated with the Navy people?

Abelson: Yes.

Groueff: And Admiral King?

Abelson: He was head of the whole thing. He was commander-in-chief.

Groueff: A visual description of the construction, what it looked like – it was in the K-25 area where the plant was? Near the Clinch River?

Abelson: Yeah.

Groueff: How would it look to the outsider if I were in the middle of the construction? Were there hundreds of workmen?

Abelson: As you can see from the picture here, this is like a long black barn.

Groueff: The building was on the river?

Abelson: Yeah, this building extended here. I guess it was about five hundred feet.

Groueff: Yeah, that’s what he says, I think. He describes it somewhere. Yeah, five hundred and twenty-five feet and seventy-five feet high. And it was noisy?

Abelson: There was one place where it would have been better if we had had a little more mechanical engineering. We were working with high pressure steam, a thousand pounds per square inch. The fittings that we were using, as it turned out we would have been much better advised if we’d had an all-welded system. But we used fittings that were screwed together. The difficulty is that if those fittings are screwed together if they ever start to leak, the high-pressure steam cuts a hole through the steel and the leak gets worse and worse.

We were running a hundred of these things at the same time so that if one started to leak, one had to shut down a great number in order to repair this. Since one was interested in the production, one let the steam hiss. It was the noise and the confusion and so on, but not anything that intrinsically kept you from working.

Groueff: But one the main characteristic features of this was the speed. They quote it as one of the records in industry?

Abelson: Oh yes.

Groueff: Seventy-five days or something. A major operation like that and a new process. I can see that it was quite exceptional.

Abelson: It was a really a remarkably fast thing to start from nothing and to do it during wartime.

Groueff: And it worked.

Abelson: Yeah.

Groueff: Did you ever write yourself on that?

Abelson: I wrote an extensive report on it.

Groueff: It must be classified now?

Abelson: It’s unclassified now. It’s technical.

Groueff: Here on the naval research project, you never wrote any articles for the large public?

Abelson: No.

Groueff: Only the technical?

Abelson: I visited the S-50 plant more than a time or two. My contact with Groves was more through the eyes of others, you might say. And of course for instance, Colonel Fox was being pushed by Groves. Fox was the kind of the man who responded to pressure, and Groves was a driving man.

I certainly would agree that a large component in achieving this fast construction had to be General Groves. This is true for several reasons. One of them was that obviously in wartime with competing demands and for scarce materials, Groves had to do a superb job of seeing to it that production bottlenecks for vital materials were taken care of. This took a driving man to do it. I know how many problems there are of that kind. The other one was that he really drove these people to get things constructed. This was done rapidly.

I don’t know about his relationships with people like Oppenheimer. I can understand how those would be abrasive. But in those areas where it came to driving through to complete construction, all the facets needed to get the plant growing, there is no doubt in my mind that Groves did a superb job.

Groueff: All of the industry people say the same thing.

Abelson: Yeah.

Groueff: Sometimes stepping on people’s toes or hurting feelings, but the job was done always.

Abelson: Yeah.

Groueff: And Nichols was also driving, but more—

Abelson: Nichols was quieter. He was a driver, but Nichols was of a different personality. I think Nichols is little more of, you could say, a scholar. He was a little more of a philosopher. Nichols had a good mind, no doubt about that.

Groueff: A different temperament?

Abelson: A different temperament and personality.

Groueff: More diplomatic also?

Abelson: More diplomatic.

Groueff: And understanding better the mentality of the PhD’s?

Abelson: Yeah.

Groueff: And Lawrence?

Abelson: I met Lawrence in Oak Ridge on two or three occasions. Since I had been a student of his, he invited me to his apartment that he had for dinner. So we had a conversation and dinner consisted of two cans of Campbell soup.

Groueff: He wasn’t thinking of anything else.

Abelson: No.

Groueff: Yeah, it fits with the rest of the description I have of him.

Abelson: In 1936, ’37, Oppenheimer became intensely concerned with the course of the war in Spain and was very sympathetic to the Loyalist cause. And in fact, Oppenheimer was active in getting money. One Sunday morning I was seated at the cyclotron all alone running a radiation, running the cyclotron, and about nine, ten o’clock, in came Oppenheimer into the radiation laboratory. There was nobody else in the place. He looked around and he went to the blackboard and he put down “Cocktail Party Benefits Spanish Loyalists,” and he gave the address of the residence, at two thirty p.m. “Bring your friends.”

About an hour later into the laboratory came Lawrence. He came over to see that I was operating properly and that everything was functioning properly in the laboratory. Of course you can understand that Lawrence in those days was like a magnificent animal who owned this particular pasture. So in surveying his domain, his eyes fell on the blackboard. You could smell the strange odor of the animal and his jaws clenched.

Lawrence turned and looked at the blackboard. You could see he was concerned. His jaws clenched as they did when he was troubled, and he walked slowly towards the blackboard and he erased all of it.

Groueff: Without saying anything?

Abelson: He didn’t say anything to me. He knew it was Oppenheimer’s writing. He made no comment whatsoever. He erased this off and shortly departed the laboratory.

Groueff: There was beginning to be some slight—

Abelson: Even in the pre-war era, Oppenheimer of course was a man who was very brilliant. In spite of his brillance however, he didn’t help us experimental people appreciably. Very little help did we get from Oppenheimer. On the other hand, Oppenheimer was so brillant that he had no trouble whatsoever in making Lawrence look bad in a seminar if Lawrence suggested something. Oppenheimer wasn’t very diplomatic about these things, so that on more than one occasion he was undiplomatic in the way that he treated Lawrence’s ideas.

I’m reminded of these stories for one reason. It is that I was completely surprised when I learned after the war that the people who were at Los Alamos considered Oppenheimer to be a magnificent leader. I was terribly surprised. I couldn’t believe it. And the reason I couldn’t believe it was that I had felt that in his interaction with the experimental science at Berkeley, during the cyclotron days when we were leaders in the world and nuclear was safe, that Oppenheimer had not given the distinguished performance in any kind of interaction or teamwork. It was incredible to me that on the basis of his behavior during the late ‘30s in Berkeley that Oppenheimer should do so well at Los Alamos, that it’s just possible. The key might have been your General Groves. I don’t know. I’d be interested if some of the others at Berkeley at the time would have any kind of a similar impression. But I studied Oppenheimer very closely during the studies and I would have no more have been willing to believe he was successful in that kind of undertaking.

Groueff: There was a coolness about his domination from [James B.] Conant, [Vannevar] Bush, and all of the important people. Groves didn’t know them. Groves also actually said, “I knew what I needed. Give me another Lawrence and I’ll make him a heaven, but where do you find him?” So that was Groves’ idea, to find a Lawrence. And Lawrence couldn’t come because the electromagnetics would collapse without him. So as a second, “Because we cannot have Lawrence, who will be a second one?” They went through the list of the top scientists.

The program leader couldn’t be [Arthur] Compton. [Enrico] Fermi was a foreigner and wouldn’t be an administrator. [Harold] Urey was absolutely out of the question because he was a poor administrator. [John] Dunning was too young. Most of those people were involved in what Groves believed—and he’s probably right—the main thing, and actually less glamarous for the large public, the main difficulty was the separation.

Abelson: Was to get the materials.

Groueff: Because if you have the material, of course the rest is difficult, but that’s the main thing. The big battle would be in getting the material. So you shouldn’t disturb any one of those programs. There was nobody left. And he was impressed by Oppenheimer’s intelligence. He was a superiorly intelligent man. And probably he thought he could keep him in hand and he did.

Abelson: The answer which you undoubtedly heard many times in talking to people at Los Alamos, those who were there just really placed Oppenheimer on a high pedastal.

Groueff: Absolutely.

Abelson: He really showed unique qualities in that period.

Groueff: Probably all of us sometimes we change under different circumstances. Like in the war is a good example, nobody would believe that this guy—

Abelson: There’s just no doubt that Oppenheimer was a different person at Los Alamos than he was in the pre-war. He was quite different in his capabilities and effectiveness. It’s true that in the pre-war days he did have the devoted following of a number of young theoretical physicists. But he gave one entirely this impression of going around in a fog half of the time.